The present invention is directed to a deployment door that is opened upon inflation of an air bag from an air bag module mounted in a vehicle.
It is known to use an inflatable air bag in a vehicle to help protect a vehicle occupant in the event of a vehicle collision. The air bag is inflated by inflation fluid from an actuatable inflator. The inflator and the air bag are typically assembled together in an air bag module. The air bag module also includes a reaction canister, which contains and supports the air bag and the inflator. The reaction canister has a deployment opening through which the air bag moves when inflated by the inflator. A deployment door is secured over the deployment opening to conceal the air bag module in the vehicle. Deployment doors are often manufactured by applying a urethane foam over a metal substrate. It is known to punch additional openings in the substrate to aid in material flow during the foaming process. It is also known to place openings in the substrate to weaken the substrate in an area where hinging action of the deployment door is desired.
In the event of a vehicle collision, the inflator is actuated and begins to inflate the air bag with inflation fluid from the inflator. As the air bag inflates, the air bag moves through the deployment opening and engages the deployment door. The inflating air bag pushes against the deployment door, causing the deployment door to pivot about a weakened hinge portion of the deployment door. The inflating air bag thus opens the deployment opening by pivoting the deployment door away from the deployment opening so that the air bag can inflate into the passenger compartment of the vehicle.
The deployment door may contact parts of the occupant""s body, such as the occupant""s head. The deployment door can then transfer the force of the inflating air bag to the occupant""s head until the occupant""s head is moved far enough away from the deployment opening for the air bag to continue inflating and expanding into the passenger compartment. A deployment door that flexes around a vehicle occupant would allow the air bag to expand laterally around the sides of the deployment door and thereby reduce the force transferred to the occupant""s body during deployment of the air bag.
The present invention is an apparatus for use in a vehicle. The apparatus comprises an air bag module mounted in the vehicle. The air bag module includes an inflatable air bag for helping to protect a vehicle occupant in the event of a vehicle collision and an opening through which the air bag deploys when inflated. A deployment door covers the opening. The deployment door includes a first edge and a hinge area extending parallel to the first edge. The hinge area has an attachment portion connected to the vehicle and a hinge portion at which the deployment door pivots to allow the air bag to deploy. The hinge portion has oppositely disposed first and second ends. The deployment door has a second edge disposed opposite the first edge. The second edge includes a central portion. The deployment door further includes first and second areas of reduced stiffness. The first area of reduced stiffness extends from the first end of the hinge portion toward the central portion of the second edge and defines a first side section of the deployment door. The second area of reduced stiffness extends from the second end of the hinge portion toward the central portion of the second edge and defines a second side section of the deployment door. The first and second areas of reduced stiffness enable the first and second side sections, respectively, of the deployment door to flex around parts of the vehicle occupant that may be blocking pivotal movement of the deployment door during deployment of the air bag.
The deployment door comprises a substrate made of a relatively rigid first material and an outer layer made of a relatively flexible second material that is applied to the substrate.
In accordance with one embodiment of the present invention, the substrate includes an array of first apertures that form the first area of reduced stiffness in the deployment door and an array of second apertures that form the second area of reduced stiffness in the deployment door.
In accordance with another embodiment of the present invention, the substrate includes a first set of ribs in the first side section of the deployment door, a second set of ribs in the second side section of the deployment door, and a centrally located third set of ribs. The first area of reduced stiffness in the deployment door is defined between the first set of ribs and the third set of ribs. The second area of reduced stiffness in the deployment door is defined between the second set of ribs and the third set of ribs.